Measurements of the magnetic response to an oscillating magnetic field are used routinely in the study of metals and magnetic insulators. For example, the thermodynamic behavior of the vortex lattice in a superconductor is more pronounced in an oscillating magnetic field because vortex pinning is less of an issue.[1]}, [2]}, [3]}, [4]} Recently, “orientation oscillation” measurements, whereby the angle between a sample and a static magnetic field is varied periodically in time, have been used to study the intrinsic properties of metals and magnetic insulators. [5]}, [6]}, [7]}, [8]} In these measurements, the resonance frequency of an oscillating sample-cantilever assembly shifts in response to changes in magnetic energy of the sample in an external magnetic field. The frequency shift is proportional to the magnetotropic susceptibility  of the sample.
